(i) Field of the Invention
The present invention relates to clutches in general and in particular to a novel spiral type one-way clutch mechanism. It also relates to novel overrunning spiral type one-way clutches of the roller ramp type.
(ii) Description of the Prior Art
One-way clutches presently in existence include sprag, friction wedge, and roller ramp type, which generally consist of a plurality of individually activated jamming elements that are radially located between the concentric, clutching members.
Risinger, in U.S. Pat. No. 524,652 patented Aug. 14, 1899, provided a bicycle including an intermittent grip mechanism including three distinct crescent shaped wedges disposed concentric to, but outboard of a ratchet portion, with a series of rollers interposed between the opposing edges of the wedges and the ratchet faces to facilitate movement of the wedges.
Constantinesco, in U.S. Pat. No. 1,618,915 patented Feb. 22, 1927, provided a unidirectional driving device including an annular rotor; a concentrically disposed series of separate wedge-shaped crescent members; and elastic roller bearings disposed in the space between the rotor and the wedge-shaped members.
Dodge, in U.S. Pat. No. 2,785,782 patented Mar. 19, 1957, provided a wedge type one-way clutch including an annular outer race, an inner race and a plurality of outer wedge/inner wedge crescent elements disposed therebetween, with each outer wedge/inner wedge crescent element including a plurality of cylindrical rollers therebetween.
Fulton, in U.S. Pat. No. 3,202,250 patented Aug. 21, 1965, provided an annular outer race, a cylindrical inner race, and a spiral wedge acting as a gripping member, with a surface coating of low friction material between the spiral wedge and the outer race.
Ollagnon et al. in French Pat. No. 891,793 patented Mar. 20, 1944 disclosed a one-way clutching mechanism including an annular outer race composed of a plurality of wedge-shaped crescent elements, an inner race composed of a plurality of wedge-shaped crescent elements, with rollers disposed between the outer race and the inner race.
Other patents which disclose one-way clutching mechanisms include:
U.S. Pat. Nos. 184,273, 300,503, 1,834,843, 1,855,690, 1,893,231, 1,931,317, 1,946,043, 3,021,925, 3,107,764, 3,937,311, 3,368,834, 3,595,354, 3,326,345.
French Pat. No. 1,005,049.
Canadian Pat. Nos. 544,146, 965,360.
The clutching mechanisms disclosed in the above-discussed prior art patents have some or all of the following operating characteristics: (a) uniform distribution of the clutching load depends on identical kinematic response of the jamming-elements; (b) transverse forces, such as those caused by a simultaneous rotation of the geometric axis of the clutch assembly around a second axis, increase the disarray in the response of the jamming-elements; and (c) the critically shaped surfaces of the jamming-elements can be subject to frictional wear when in the overrunning mode.